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  1. 20 Aug, 2012 1 commit
    • Tejun Heo's avatar
      workqueue: deprecate system_nrt[_freezable]_wq · 3b07e9ca
      Tejun Heo authored 
      
system_nrt[_freezable]_wq are now spurious.  Mark them deprecated and
convert all users to system[_freezable]_wq.

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant, so there's no reason to use system_nrt[_freezable]_wq.
Please use system[_freezable]_wq instead.

This patch doesn't make any functional difference.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-By: default avatarLai Jiangshan <laijs@cn.fujitsu.com>

Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
      3b07e9ca
  3. 14 Aug, 2012 1 commit
  5. 22 Jul, 2012 1 commit
  7. 30 Jun, 2012 1 commit
  9. 28 Jun, 2012 1 commit
  11. 11 Jun, 2012 1 commit
  13. 30 May, 2012 1 commit
  15. 17 May, 2012 1 commit
    • Michael S. Tsirkin's avatar
      virtio_net: invoke softirqs after __napi_schedule · ec13ee80
      Michael S. Tsirkin authored 
      
__napi_schedule might raise softirq but nothing
causes do_softirq to trigger, so it does not in fact
run. As a result,
the error message "NOHZ: local_softirq_pending 08"
sometimes occurs during boot of a KVM guest when the network service is
started and we are oom:

  ...
  Bringing up loopback interface:  [  OK  ]
  Bringing up interface eth0:
  Determining IP information for eth0...NOHZ: local_softirq_pending 08
   done.
  [  OK  ]
  ...

Further, receive queue processing might get delayed
indefinitely until some interrupt triggers:
virtio_net expected napi to be run immediately.

One way to cause do_softirq to be executed is by
invoking local_bh_enable(). As __napi_schedule is
normally called from bh or irq context, this
seems to make sense: disable bh before __napi_schedule
and enable afterwards.

In fact it's a very complicated way of calling do_softirq(),
and works since this function is only used when we are not
in interrupt context.  It's not hot at all, in any ideal scenario.
Reported-by: default avatarUlrich Obergfell <uobergfe@redhat.com>
Tested-by: default avatarUlrich Obergfell <uobergfe@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
      ec13ee80
  17. 15 Apr, 2012 1 commit
    • Jason Wang's avatar
      virtio-net: send gratuitous packets when needed · 586d17c5
      Jason Wang authored 
      
As hypervior does not have the knowledge of guest network configuration, it's
better to ask guest to send gratuitous packets when needed.

This patch implements VIRTIO_NET_F_GUEST_ANNOUNCE feature: hypervisor would
notice the guest when it thinks it's time for guest to announce the link
presnece. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change interrupt
and woule send gratuitous packets through netif_notify_peers() and ack the
notification through ctrl vq.

We need to make sure the atomicy of read and ack in guest otherwise we may ack
more times than being notified. This is done through handling the whole config
change interrupt in an non-reentrant workqueue.
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      586d17c5
  19. 13 Apr, 2012 1 commit
  21. 28 Mar, 2012 1 commit
  23. 15 Feb, 2012 1 commit
  25. 13 Feb, 2012 1 commit
  27. 12 Jan, 2012 4 commits
  29. 05 Jan, 2012 1 commit
  31. 29 Dec, 2011 2 commits
    • Rusty Russell's avatar
      virtio_net: use non-reentrant workqueue. · f1776dad
      Rusty Russell authored 
      
Michael S. Tsirkin also noticed that we could run the refill work
multiple CPUs: if we kick off a refill on one CPU and then on another,
they would both manipulate the queue at the same time (they use
napi_disable to avoid racing against the receive handler itself).

Tejun points out that this is what the WQ_NON_REENTRANT flag is for,
and that there is a convenient system kthread we can use.
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f1776dad
    • Rusty Russell's avatar
      virtio_net: set/cancel work on ndo_open/ndo_stop · b2baed69
      Rusty Russell authored 
      
Michael S. Tsirkin noticed that we could run the refill work after
ndo_close, which can re-enable napi - we don't disable it until
virtnet_remove.  This is clearly wrong, so move the workqueue control
to ndo_open and ndo_stop (aka. virtnet_open and virtnet_close).

One subtle point: virtnet_probe() could simply fail if it couldn't
allocate a receive buffer, but that's less polite in virtnet_open() so
we schedule a refill as we do in the normal receive path if we run out
of memory.
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b2baed69
  33. 20 Dec, 2011 1 commit
  35. 09 Dec, 2011 1 commit
  37. 26 Nov, 2011 1 commit
  39. 16 Nov, 2011 1 commit
  41. 02 Nov, 2011 1 commit
  43. 24 Oct, 2011 1 commit
  45. 21 Oct, 2011 1 commit
  47. 20 Oct, 2011 1 commit
  49. 19 Oct, 2011 1 commit
  51. 06 Oct, 2011 1 commit
    • Sasha Levin's avatar
      virtio-net: Verify page list size before fitting into skb · e878d78b
      Sasha Levin authored 
      
This patch verifies that the length of a buffer stored in a linked list
of pages is small enough to fit into a skb.

If the size is larger than a max size of a skb, it means that we shouldn't
go ahead building skbs anyway since we won't be able to send the buffer as
the user requested.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: default avatarSasha Levin <levinsasha928@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e878d78b
  53. 22 Sep, 2011 1 commit
  55. 18 Aug, 2011 1 commit
  57. 22 Jul, 2011 1 commit
  59. 01 Jul, 2011 1 commit
  61. 11 Jun, 2011 1 commit
    • Jason Wang's avatar
      virtio_net: introduce VIRTIO_NET_HDR_F_DATA_VALID · 10a8d94a
      Jason Wang authored 
      
There's no need for the guest to validate the checksum if it have been
validated by host nics. So this patch introduces a new flag -
VIRTIO_NET_HDR_F_DATA_VALID which is used to bypass the checksum
examing in guest. The backend (tap/macvtap) may set this flag when
met skbs with CHECKSUM_UNNECESSARY to save cpu utilization.

No feature negotiation is needed as old driver just ignore this flag.

Iperf shows 12%-30% performance improvement for UDP traffic. For TCP,
when gro is on no difference as it produces skb with partial
checksum. But when gro is disabled, 20% or even higher improvement
could be measured by netperf.
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      10a8d94a
  63. 30 May, 2011 1 commit
  65. 02 Apr, 2011 1 commit
  67. 10 Feb, 2011 1 commit
  69. 16 Dec, 2010 1 commit
  71. 12 Nov, 2010 1 commit